1. Field of the Invention
The present invention relates to an image processing apparatus, and particularly to an image processing apparatus capable of effectively removing noise included in image signals, an image capturing apparatus, an image processing method in these apparatuses, and a program allowing a computer to execute the method.
2. Description of the Related Art
RAW data output from an imaging device, such as a CCD (charge coupled device), includes various types of noise. As a method for effectively removing the noise, a method for changing a level of denoising in consideration for a visual characteristic of humans has been widely known.
For example, there has been suggested an image processing method for determining colors of an image on which noise is superimposed in units of areas of a predetermined size, deciding a parameter in accordance with the determined colors, and performing a denoising process in accordance with the decided parameter (e.g., see Patent Document 1: Japanese Unexamined Patent Application Publication No. 2004-40235 (FIG. 1)).